I believe it's the same group that made Team Fortress 2. It's team based FPS set up a lot like L4D sort of. You can play seperate maps like any other FPS, but the main "mode" is where you basically play through the campaign against other players/bots will take over if not enough players. Think Killzone 3's mode w/ cutscenes but a lot longer.

You can also customize the hell out of your guns/character which is a nice feature in my opinion. You also have the choice to play between 1 of the 2 "Factions", however, you can play both if you want, which will also result in a different "campaign" playthrough between singleplayer/multiplayer.